Falls in the elderly may represent a substantial healthcare problem worldwide. Indeed, a significant percentage of people over seventy years of age experience a significant fall, and the frequency of falls increases with age and the level of frailty.
Increased frailty and declining balance may be reflected in how a person walks. The task of walking is a complex motor control challenge, where the human neuromuscular system is required to interact with the environment while maintaining balance during forward momentum. A person must maintain a safe foot trajectory with respect to the ground. Foot trajectory during the swing phase of a person's gait can be sensitive to small angular changes at six other joints within both stance and swing limbs. The sensitivity suggests that foot trajectory involves precise end-point control task. Disturbance of this end-point control may lead to falls or other unprovoked collisions with the ground.
One falls-related parameter measured during walking trials is minimum ground clearance (MGC), which has also been called minimum toe clearance (MTC). The parameter generally reflects how much the walking trial participant lifts his or her foot from the ground during a walk. The MGC may be measured in a specialized gait clinic that uses marker-based optical motion capture systems. The specialized optical motion capture equipment may be operated by specialized personnel to analyze the MGC of the participant.